New hue of blue - The West Australian

Brenna Harding is kneeling on the bed her fictional parents share on Ten's Puberty Blues.

She's blowing on a hot chocolate cupped in one hand and has an Arnott's biscuit in the other.

If the cameras happened to grab some shots she would have no problem passing as her character Sue Knight.

Like Sue, the 17-year-old is enthusiastic and bubbly yet pensive - a strange amalgam of adult and child. It's nice to see her so comfortably adolescent despite her quick rise to fame after the first season aired in 2012 and for which she won the most popular new female talent Logie (she was also the girl with two mums on Play School).

"It's been crazy, it's been mad," she says.

Still enrolled at St George Girls in Kogarah, Harding plans to complete Year 12 this year. During filming for the second season last year, she filmed 50-60 hours a week while attempting to finish Year 11.

"My part has been written up a bit more this season," she explains.

"There's an interesting dynamic set up when Sue is separated from Debbie (Ashleigh Cummings) and how she deals with that and it does liberate her a little bit because she has been trapped in a small, confined relationship of just Sue and Debbie."

Shot in and around Sydney's Sutherland Shire, the nine-part series will pick up during the summer of 1979 and it's a highly dramatic return episode with a pregnancy in the first five minutes. Sue has defied the Greenhills gang's strict rules by taking up surfing but remains in the inner circle despite not having the requisite boyfriend. Gary (Busselton-raised Sean Keenan), Debbie's boyfriend, has been garnering attention on the pro-surfing circuit and more kudos within the gang.

But their sun-soaked idyll is about to come crashing down, with Debbie's parents sending her to boarding school.

"We became really, really, really, really close in the first season because we worked pretty much with each other 12 hours a day, five days a week," Harding says of her mate and co-star Cummings.

"I'd wake up, get in the car and be on her lap and just running lines but this season is a bit different because Ash isn't around. There was an adjustment period because it didn't feel like Puberty Blues without her, but it's also nice because I'm able to find my character away from Debbie.

"Sue always followed along after Debbie, she was much more submissive when she was around Debbie, and I think she's really now finding her own power.

"The typical rebellious things she did were the things she did in the first season - getting stoned for the first time, getting drunk for the first time, having sex for the first time but I guess the rebellion in this is that she rebels against what society tells her she has to be.

"She's being feisty and she's choosing which boy that she wants to date or be interested in. She's surfing and I think that's her rebelling in the second season."

But as they say - when one door closes, a window opens. While she's missed Cummings, Harding has relished forging a closer relationship with Susie Porter, who plays her on-screen mum Pam Knight.

"In the absence of Debbie, Sue has to compensate for not having her best friend and she becomes really close with her mum and so you'll see some really beautiful scenes with me and Susie," she explains.

"You can really see that Sue's opening up and growing up. In the first season she was sneaking out and not telling her parents anything and now she's really opening up and having these really personal conversations with her mum."

In a case of life imitating art, Harding says she's learnt "bucketloads" from her on-screen parents during filming.

"It's not like working when Dan (Wyllie) and Susie are on set, we have so much fun together," she says with a grin.

"They're constantly cracking jokes and bouncing off each other. Dan's really naughty, he says a lot of naughty jokes.

"It's really nice to just sit and watch them. I think that's when I learn the most from them and I do have some really great conversations with Susie about the film industry.

"Every actor works differently and to see how they work is so helpful for me. To see that they still make mistakes sometimes and that's OK and it's OK for me to make those mistakes too and no one is judging me. They make it a really safe environment."